crypto/sha1: Make sha-1 do block mixup in place

Benchmarks:

benchmark              old ns/op    new ns/op    delta
BenchmarkHash8Bytes          762          674  -11.55%
BenchmarkHash1K             8791         7375  -16.11%
BenchmarkHash8K            65094        54881  -15.69%

benchmark               old MB/s     new MB/s  speedup
BenchmarkHash8Bytes        10.50        11.86    1.13x
BenchmarkHash1K           116.48       138.84    1.19x
BenchmarkHash8K           125.85       149.27    1.19x

R=dave, rsc, iant
CC=golang-dev
https://golang.org/cl/6820096

diff --git a/src/pkg/crypto/sha1/sha1block.go b/src/pkg/crypto/sha1/sha1block.go
index b9fe21d9e3debf3c6bc925e81b276242d086eebb..1c9507c68e523fa5461f28478de4012ec3f967fd 100644 (file)
--- a/src/pkg/crypto/sha1/sha1block.go
+++ b/src/pkg/crypto/sha1/sha1block.go
@@ -16,7 +16,7 @@ const (
 )
 
 func block(dig *digest, p []byte) {
-       var w [80]uint32
+       var w [16]uint32
 
        h0, h1, h2, h3, h4 := dig.h[0], dig.h[1], dig.h[2], dig.h[3], dig.h[4]
        for len(p) >= chunk {
@@ -26,42 +26,56 @@ func block(dig *digest, p []byte) {
                        j := i * 4
                        w[i] = uint32(p[j])<<24 | uint32(p[j+1])<<16 | uint32(p[j+2])<<8 | uint32(p[j+3])
                }
-               for i := 16; i < 80; i++ {
-                       tmp := w[i-3] ^ w[i-8] ^ w[i-14] ^ w[i-16]
-                       w[i] = tmp<<1 | tmp>>(32-1)
-               }
 
                a, b, c, d, e := h0, h1, h2, h3, h4
 
                // Each of the four 20-iteration rounds
                // differs only in the computation of f and
                // the choice of K (_K0, _K1, etc).
-               for i := 0; i < 20; i++ {
+               i := 0
+               for ; i < 16; i++ {
+                       f := b&c | (^b)&d
+                       a5 := a<<5 | a>>(32-5)
+                       b30 := b<<30 | b>>(32-30)
+                       t := a5 + f + e + w[i&0xf] + _K0
+                       a, b, c, d, e = t, a, b30, c, d
+               }
+               for ; i < 20; i++ {
+                       tmp := w[(i-3)&0xf] ^ w[(i-8)&0xf] ^ w[(i-14)&0xf] ^ w[(i)&0xf]
+                       w[i&0xf] = tmp<<1 | tmp>>(32-1)
+
                        f := b&c | (^b)&d
                        a5 := a<<5 | a>>(32-5)
                        b30 := b<<30 | b>>(32-30)
-                       t := a5 + f + e + w[i] + _K0
+                       t := a5 + f + e + w[i&0xf] + _K0
                        a, b, c, d, e = t, a, b30, c, d
                }
-               for i := 20; i < 40; i++ {
+               for ; i < 40; i++ {
+                       tmp := w[(i-3)&0xf] ^ w[(i-8)&0xf] ^ w[(i-14)&0xf] ^ w[(i)&0xf]
+                       w[i&0xf] = tmp<<1 | tmp>>(32-1)
                        f := b ^ c ^ d
                        a5 := a<<5 | a>>(32-5)
                        b30 := b<<30 | b>>(32-30)
-                       t := a5 + f + e + w[i] + _K1
+                       t := a5 + f + e + w[i&0xf] + _K1
                        a, b, c, d, e = t, a, b30, c, d
                }
-               for i := 40; i < 60; i++ {
-                       f := b&c | b&d | c&d
+               for ; i < 60; i++ {
+                       tmp := w[(i-3)&0xf] ^ w[(i-8)&0xf] ^ w[(i-14)&0xf] ^ w[(i)&0xf]
+                       w[i&0xf] = tmp<<1 | tmp>>(32-1)
+                       f := ((b | c) & d) | (b & c)
+
                        a5 := a<<5 | a>>(32-5)
                        b30 := b<<30 | b>>(32-30)
-                       t := a5 + f + e + w[i] + _K2
+                       t := a5 + f + e + w[i&0xf] + _K2
                        a, b, c, d, e = t, a, b30, c, d
                }
-               for i := 60; i < 80; i++ {
+               for ; i < 80; i++ {
+                       tmp := w[(i-3)&0xf] ^ w[(i-8)&0xf] ^ w[(i-14)&0xf] ^ w[(i)&0xf]
+                       w[i&0xf] = tmp<<1 | tmp>>(32-1)
                        f := b ^ c ^ d
                        a5 := a<<5 | a>>(32-5)
                        b30 := b<<30 | b>>(32-30)
-                       t := a5 + f + e + w[i] + _K3
+                       t := a5 + f + e + w[i&0xf] + _K3
                        a, b, c, d, e = t, a, b30, c, d
                }